I found out that my slave cylinder was leaking, that's why I couldn't bleed it.
So just remove it, place my backup cylinder and everythings fine hé?

No, I couldn't remove my old slave cylinder, I've never seen anything so stuck

I used loosening oil, I've tried to turn it with a big set of pliers and eventually I've tried to tap it with a small hammer..
I didn't use heat because everything is a bit oily on the underside of my car, we've had a fire before.. don't want it again.

The result :
ARRGHHG

Even when the part is broken off, I still can't remove it.. not even in the vice and with a bigger hammer.. it won't budge.

So yeah, now I need to create something that will hold the new slave cylinder..